An apparently normal, healthy 3-year-old boy developed redness of the left eye. An ophthalmologist discovered an intraocular tumor which he believed arose from the choroid. The child's 17-year-old mother developed osteosarcoma of the right femur during pregnancy and died a short while after his birth. Because of the rarity of malignant melanoma of the choroid in this age group, an exhaustive study was made resulting in firm evidence that this was probably a melanoma. The eye was enucleated. Pathologic study demonstrated a malignant melanoma with unusually pleomorphic cells.